Process for producing high-grade rosin and turpentine



May 28, 1940. sg s 2,202,028

PRocEss Fon rnonucme HIGH-GRADE ROSIN AND TURPENTINE Filed Jan. 18, 1938 5 price.

Patented May 28 1940 UNITED STATE-SH PATENT orrice PROCESS FOR rnonuonvo HIGH-GRADE ROSINAND TURPENTINE JoseplrA. Scruggs, Pensacola, Fla. Application January 18, 1938, Serial No. 185,593

2 Claims.

My invention relates to an improved process for producing high-grade rosin and turpentine. The extraction of turpentine and pine oil from wood chips by the use of steam, with or without vacuum is now in common use. In processes heretofore employed, the rosin must be first produced by the solvent or other well-known methods, and is, thereafter, refined by chemical treatment or by distillation or by both methods combined. In the ordinary distillation process, the rosin is often injured by contact with hot metal when raised to the temperature necessary-for distillation, and in some cases due to the presence of air.

Rosin has also been produced by the so-called "destructive distillation processes, but it has been of an extremely low grade.

The ordinary retort produces a grade of rosin known as FF. Some producers then put the rosin through one or more additional processes to produce a higher grade of rosin. This additional process requires considerable time and the use of expensive machinery and formulae, which;

consequently. add greatly to the cost and market Ihe-following are among the objects of my present invention:

First, to produce a product of higher grade and at a greatly reduced production cost as compared with other processes hitherto and now in use, and to this end my improved product is produced by a single process without the necessity for further refining.

This present invention involves a new principle in the distillation of rosin directly from the wood chips, instead of destructive distillation in which the necessary excessive heat destroys the wood, but by my present improved process there is produced a high-grade rosin by means of the :0 first operation as distinguished from other methods of manufacture in which a low grade rosin is first produced and thereafter refinedby succeeding processes in order to raise the grade, thus in my processavoidlng the added cost of L5 further purification. 7

The four figures of the drawing illustrate four slightly varying apparatus in which my improved process may be carried out.

- Referring to Fig. 1, A is a vessel in which chips 50 of wood are placed. This is sealed tight. Heat is applied by means of steam entering through the steam pipe After the chips are brought to a temperature in the neighborhood of 320 F.,

a valve 2 is openedand vacuum is applied by 55 vacuum pump 3 through the condenser 4, and

under these conditions spirits are distilled off.

This cycle may be repeated if found necessary 50 the chips hot.

valve 5 in the steam pipe are closed. The steam now in vessel A is circulated through the blower 6 and superheater I located immediately below vessel A, and then through the chips in vessel A continuously. Incidentally, the superheater I is preferably placed immediately beneath the vessel A,'in order. that the hot gas after passing around the superheater' may be used to prevent radiation loss from vessel A.

This superheated steam thoroughly dries the chips. Excess steam generated from any moisture in the chips is drawn 011 through the condenser 4, vacuum being applied through the condenser by means of the vacuum pump 3 to remove the steam, after which the valve 2 to the condenser is closed.

At this point in the process, a liquid, for example gasoline or certain other hydrocarbon mixtures, is introduced through pipe 8 controlled by valve 9 therein, into the vessel A. This liquid passes through the blower 6,-to the superheater I where it is vaporized. Sufiicient liquid is pumped in to build up a pressure of about one hundred twenty-five (125) pounds to the square inch. Gas from the liquid is circulated through the superheater until the chips reach a temperature of about 520 F. A valve I0 in the pipe ll leading to a condenser I2 is then opened and vacuum is applied by the vacuum pump l3 in connection with the condensers l2 and I4, and a filter and separator l5.

By means of this vacuum, the heat stored in the chips, and the action of the gas through the chips,'the rosin is vaporized from the chips and passes immediately to condenser l2 where the rosin is condensed with part of the gas, and the balance of the gas passes to condenser M, where it is condensed to be used again. The condensed rosin with its condensed gas first passes through a filter or separator to a still l6. I

The foregoing cycle is repeated until the rosin is entirely vaporizedfrom the chips.

The liquid with the rosin' in the still I6 is distilled oil through the condenser H to a reservoir 18. The rosin may be drawn off directly from the bottom of the still lli'through a cook 19.

Referring now to the showing in Fig. 2, the same numerals have been employed up to and including I2 to corresponding parts, since the two apparatus are the same up to and including this point. In the form shown in Fig. 2, there are three rosin condensers 20, 2| and 22, in series with the idea of producing three grades of rosin, if desired. For each condenser, there is a separator, and these are numbered 23, 24 and 25, and a corresponding number of reservoirs, 27 and 28 are provided, that is to say there are a series A through the pipe ll, pipes 30 leading from the rosin condensers to the separators, and pipes 3| leading from the separators to the condensers 2| and 22, and pipes 32 leading to the several reservoirs 26, 21 and 26, and from these reservoirs, the rosin flows through the pipes 33, preferably to a common still 34, valves I0 being provided in. each of these pipes to be used when required. From the still 34, a pipe 35 leads to a condenser 36, and another pipe 31 may lead directly from the separator 25 to the condenser 36, and a vacuum pump 38 is connected with the pipe leading from the condenser 36 to the reservoir 39.

In the construction illustrated-in Fig. 3, the letter A and the numerals I, 2, 3, 4, 5, 6, I, 8, 9, l0 and II are the same and represent the corresponding parts described in connection with Figs. 1 and 2, and hence are not repeated. In this connection, the parts 3 and 4 are duplicated as 30 and 4a, thus providing separate condensers for spirits and pine oil,-the numeral 4 representing the spirits condenser, and 4a the pine oil condenser.

The pipe H leads to a rosin condenser 40, and from the condenser 40 to a separator 4i, and 42 represents a pump. A pipe 43 leads from the pump 42 to a continuous still 44. From the separator 4!, a pipe 45 leads to a condenser 46, from which latter one pipe 41 leads to the continuous still 44, and another pipe 48 to a vacuum pump 49, and thence to a reservoir 50.

In the construction shown in Fig. 4, a blower Si is located in the pipe ll between it and the valve l0, and from the rosin condenser 52 a pipe 53 leads into another condenser 54, and from condenser 54 one pipe 55 leads to a condenser 56 and a vacuum pump 51 withdraws the rosin to a condenser 58, and from there it is carried'to a reservoir 59. The pipe 60 extends from the rosin condenser 54 to a continuous still 6|, and a pipe 62 leads from this still to a condenser 53 from which the condensation is removed by a vacuum pump 64 to a reservoir 65. A blower 5| is provided to accelerate the movement of the gas and vapor through these several condensers. The blower might be placed in the pipe 55 between the two condensers 54 and 56, if desired.

A blower might, of course, be used, if desired, withthe previously described apparatus.

The superheated gas in my improved process imparts the heat necessary to the chips without the rosin coming in contact with metal and without overheating any part of the rosin as is frequently the case, as has been previously pointed out, when rosin is heated to the necessary temperature by ordinary methods of distillation.

My improved process uses a smaller quantity of gas'oline or other hydrocarbons than is used by various solvents and processes.

The distilling off of the spirits and pine oil by steam may be done in cycles as has been described, or may be done continuously. The spirits and pine oil are preferably distilled off before the superheated gas is circulated through the chips. In my improved process, the rosin as well as the spirits and pine oil are vaporized from the chips by means of a hot dry gas, thus leaving most of the impurities and coloring matter in the chips.

As an illustration, the use of a blower permits the evaporation of a given weight of rosin, say with two hundred (200) gallons of gasoline. This two hundred gallons of gasoline is heated to the vapor point, then the latent heat of evaporation is applied to the two'hundred gallons 0! gasoline, then the vapor therefrom is superheated to the desired degree and circulated through the chips by the blower, giving off some.

of the superheat to the chips. It is then circulated through the blower and superheater to replace the superheat given oil to the chips. This 'cycle is repeated until the chips are brought to the desired temperature and until, by repeated applications, the latent heat of evaporation of the rosin has been stored in the chips.

Without the use of the blower, eight thousand (8,000) gallons instead of two hundred (200) gallons of gasoline would be required for the evaporation of the same given weight of rosin. This would represent a prohibitive cost due to the great quantity of heat required and the quantity of gasoline lost in the process because the eight thousand gallons of gasoline would have to be heated, first to the vapor point, then the late t heat of evaporation applied to the eight thousa desired degree. The same small percentage is lost in each case, say, for example, approximately 2%; however 2% of eight thousand (8,000) gallons is one hundred sixty (160) gallons, an excessive loss, whereas 2% of two hundred (200) gallons is only (4) gallons loss with the blower.

The rate of expansion of the superheated gas to the vacum desired is so controlled that isothermal expansion is practically obtained. During evaporation of the rosin from the chips a small quantity of gas is fed through the superheater to pass off with the rosin vapor.

Finally, it may be stated that my improved process does not destroy the wood which may be used later for fuel or any other purposes.

I claim:

1. A process of producing from particles of coniferous wood, turpentine, pine oil and a purified and decolorized rosin, by placing a charge of said wood particles in a vessel, sealing the vessel, circulating the steam through the charge to remove the turpentine and pine oil, removing the residual moisture; then recycling through the charge without condensation superheated hydrocarbon gas of the character of gasoline, which will not crack at the temperatures used, and which superheated gases increase the temperature of the charge to about 520 F.; then drawing from the vessel the hydrocarbon gases by application of vacuum, and then drawing off the purified and decolorized rosin by vacuum distillation induced by the stored heat.

2. A process of producing from particles of coniferous wood, turpentine, pine oil and a purified and decolorized rosin, by placing a charge of said wood particles in a vessel, sealing the vessel, circulating the steam through the charge to remove the turpentine and pine oil, removing the residual moisture; then recycling through the charge without condensation superheated hydrocarbon gas of the character of gasoline, which will not crack at the temperatures used, and which superheated gases increase the temperature of the charge to about 520 F.; then drawing from the vessel the hydrocarbon gases by application of vacuum, whereby the rosin is va- 

